Your Runoff in A Few Simple Steps!

The general rule of thumb is for 1,000 square feet of catchment surface, each inch of rain produces 600 gallons of harvestable water. With an average of 44 inches of rain per year in Marin County, that amounts to 26,400 gallons!

Said another way:One inch of rain on a thousand square foot roof = Approximately 600 gallons!44 inches of rain per year on a thousand square foot roof = Approximately 26,400 gallons!